And yes, there are some jokes about NBC.
Some samples from the monologue as found at Variety are below:
"I'm happy to report that we're already no. 1 in TBS's key demographic, people who can't afford HBO. I'm going to be honest: It's not easy doing a late-night show on a channel without a lot of money and that viewers have trouble finding. So that's why I left NBC."
"A lot's happened in the news since I went off the air and I was hoping I could cover it all in one joke. But then I realized that's like trying to keep an Icelandic volcano from wearing Lady Gaga's meat dress while a trapped Chilean miner cleans up the BP oil spill…Brett Favre's penis."